26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



inside the hive, 29 were received without signs of hostility; the 

 guards offered to attack one ; four were attacked very Hghtly ; and 

 six were attacked lightly. 



These results explain why the workers in the top super of a tier 

 of supers on a hive body are attacked by the guards of their hive 

 should they escape from the super and try to pass into the hive 

 through the entrance. 



10. ODOR EMITTED BY NURSE BEES 



Twenty middle-aged workers from a frame of hive No. 67 were 

 put into each of the 10 glass observation cases, then a nurse bee from 

 hive No. 23 was introduced into each case. Of the 10 nurse bees 

 tested, the workers offered to attack two ; four were attacked lightly ; 

 and four were attacked quite forcibly. 



No experiments to test the odor emitted by wax generators could 

 be devised, other than ones similar to those described just above, 

 but the above experiments really deal with the hive odor rather than 

 with the odor peculiar to nurse bees. 



II. ODOR EMITTED BY POLLEN CARRIERS 



To determine whether strange pollen carriers are accepted with 

 less hostihty than are strange workers without pollen, the following 

 experiments were prosecuted. Twenty middle-aged workers from 

 a frame of hive No. 73 were put into each of the 10 glass observa- 

 tion cases. A pollen carrier entering hive No. 81 was introduced 

 into each of the 10 cases. Five of the 10 introduced pollen carriers 

 were received peacefully and were fed, while the other five were 

 attacked lightly. In three instances the bees in the cases ate the 

 pollen on the legs of the pollen carriers. This set of experiments 

 was repeated twice by using strange workers from various hives. 

 Of the 20 pollen carriers tested, the bees showed no signs of hos- 

 tility toward three; they attempted to attack seven; and 10 were 

 attacked lightly. In five instances the pollen on the legs of the bees 

 was eaten. These experiments were again repeated twice, but in 

 these two sets strange workers from the entrances of various hives 

 were put into the cases and the pollen carriers were taken from the 

 entrances of other hives. Of the 20 pollen carriers tested, no signs 

 of hostility were shown toward four ; the workers attempted to attack 

 five ; 10 were attacked lightly ; and one was attacked quite forcibly. 

 The workers cleaned and ate the pollen from the legs of most of these 

 pollen carriers. 



